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1.
Mycoses ; 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32048335

RESUMO

BACKGROUND: Monitoring of superficial mycoses requires more attention due to their important incidence, health costs and antifungal drugs consumption. OBJECTIVES: The objectives were to estimate the burden of superficial mycoses in Belgium and to assess trends in associated antifungal consumption. METHODS: The burden of dermatophytoses (including onychomycosis) as well as skin and genital candidiasis was estimated using Disability-Adjusted Life Years (DALY). Moreover, trends in systemic and topical antifungal consumption in ambulatory care were examined for the period 2010-2017, together with their associated costs. RESULTS: Due to their high incidence and long treatment duration, dermatophytoses represented the bulk of the burden, accounting for 92.2% of the total DALYs of superficial mycoses. Terbinafine was the most prescribed antifungal in terms of doses (35.4% of the total doses) while fluconazole was the most delivered drug in terms of packages (29.1% of the total packages). More than 70% of the prescriptions were made by general practitioners while consumption varied according to age and gender of the patients. A global 12% decrease of antifungal prescriptions was observed between 2011 and 2017. However, this reduction would result mainly from packaging changes and increased self-medication. A significant decrease in itraconazole treatments was notably compensated by an increased prescription of fluconazole packages. CONCLUSION: This study emphasizes that dermatological presentations of superficial mycoses are the most important in terms of both burden and antifungal consumption in Belgium. Further reduction of antifungals use can be achieved by applying the adequate treatment after identification of the causative agent.

2.
J Am Soc Nephrol ; 30(8): 1534-1545, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31285285

RESUMO

BACKGROUND: Gitelman syndrome is a salt-losing tubulopathy caused by mutations in the SLC12A3 gene, which encodes the thiazide-sensitive sodium-chloride cotransporter. Previous studies suggested an intermediate phenotype for heterozygous carriers. METHODS: To evaluate the phenotype of heterozygous carriers of pathogenic SLC12A3 mutations, we performed a cross-sectional study of patients with Gitelman syndrome, heterozygous carriers, and healthy noncarriers. Participants measured their BP at home for three consecutive days before hospital admission for blood and urine sampling and an oral glucose tolerance test. RESULTS: We enrolled 242 participants, aged 18-75 years, including 81 heterozygous carriers, 82 healthy noncarriers, and 79 patients with Gitelman syndrome. The three groups had similar age, sex ratio, and body mass index. Compared with healthy noncarriers, heterozygous carriers showed significantly higher serum calcium concentration (P=0.01) and a trend for higher plasma aldosterone (P=0.06), but measures of home BP, plasma and urine electrolytes, renin, parathyroid hormone, vitamin D, and response to oral glucose tolerance testing were similar. Patients with Gitelman syndrome had lower systolic BP and higher heart rate than noncarriers and heterozygote carriers; they also had significantly higher fasting serum glucose concentration, higher levels of markers of insulin resistance, and a three-fold higher sensitivity to overweight. According to oral glucose tolerance testing, approximately 14% of patients with Gitelman syndrome were prediabetic, compared with 5% of heterozygous carriers and 4% of healthy noncarriers. CONCLUSIONS: Heterozygous carriers had a weak intermediate phenotype, between that of healthy noncarriers and patients with Gitelman syndrome. Moreover, the latter are at risk for development of type 2 diabetes, indicating the heightened importance of body weight control in these patients.

3.
Blood Adv ; 3(11): 1702-1713, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31171507

RESUMO

The bioactive lipid mediator sphingosine 1-phosphate (S1P) was recently assigned critical roles in platelet biology: whereas S1P1 receptor-mediated S1P gradient sensing was reported to be essential for directing proplatelet extensions from megakaryocytes (MKs) toward bone marrow sinusoids, MK sphingosine kinase 2 (Sphk2)-derived S1P was reported to further promote platelet shedding through receptor-independent intracellular actions, and platelet aggregation through S1P1 Yet clinical use of S1P pathway modulators including fingolimod has not been associated with risk of bleeding or thrombosis. We therefore revisited the role of S1P in platelet biology in mice. Surprisingly, no reduction in platelet counts was observed when the vascular S1P gradient was ablated by impairing S1P provision to plasma or S1P degradation in interstitial fluids, nor when gradient sensing was impaired by S1pr1 deletion selectively in MKs. Moreover, S1P1 expression and signaling were both undetectable in mature MKs in situ, and MK S1pr1 deletion did not affect platelet aggregation or spreading. When S1pr1 deletion was induced in hematopoietic progenitor cells, platelet counts were instead significantly elevated. Isolated global Sphk2 deficiency was associated with thrombocytopenia, but this was not replicated by MK-restricted Sphk2 deletion and was reversed by compound deletion of either Sphk1 or S1pr2, suggesting that this phenotype arises from increased S1P export and S1P2 activation secondary to redistribution of sphingosine to Sphk1. Consistent with clinical observations, we thus observe no essential role for S1P1 in facilitating platelet production or activation. Instead, S1P restricts megakaryopoiesis through S1P1, and can further suppress thrombopoiesis through S1P2 when aberrantly secreted in the hematopoietic niche.

4.
Open Forum Infect Dis ; 6(6): ofz174, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31198814

RESUMO

This study aimed to determine dolutegravir cerebrospinal fluid (CSF) diffusion in 13 patients with HIV-related cerebral impairment enrolled in a real-life observational study. Dolutegravir median (range) CSF concentration [9.6 (3.6-22.8) ng/mL] reached CSF therapeutic concentrations whatever the blood-brain barrier status and diffused in correlation with the albumin quotient (P = .0186).

5.
J Vet Diagn Invest ; 31(3): 471-474, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30943879

RESUMO

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as a reliable method to identify fungal isolates. The success of this approach relies on the availability of exhaustive databases, but the latter were built with a focus on human pathogens. We assessed a large in-house database of reference spectra and a dedicated web application for their suitability for use in veterinary laboratories. A panel of 290 mold and yeast isolates representing 69 different fungal species was isolated from various animals (including pets, cattle, and zoo animals) and identified using both MALDI-TOF MS and conventional techniques. The performance of the 2 methods was compared, and identifications were confirmed by DNA sequencing. MALDI-TOF MS allowed distinction between some closely related species and achieved 89% correct identification at the species level. In comparison, only 60% of the isolates were correctly identified with conventional approaches. Using this online application, MALDI-TOF MS thus appears to be a relevant alternative for the identification of fungal isolates encountered by animal health professionals.


Assuntos
Animais de Zoológico , Bovinos , Fungos/isolamento & purificação , Tipagem de Sequências Multilocus/veterinária , Animais de Estimação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/veterinária , Medicina Veterinária/métodos , Animais , Bases de Dados Factuais , Tipagem de Sequências Multilocus/métodos , Sistemas On-Line , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Leveduras/isolamento & purificação
6.
J Clin Lipidol ; 13(3): 468-480.e8, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31003938

RESUMO

BACKGROUND: Familial apolipoprotein A-I (apoA-I) deficiency (FAID) involving low levels of both apoA-I and high-density lipoprotein (HDL) cholesterol is associated with accelerated atherosclerosis. OBJECTIVE: The objective of this study was to define distinctive patterns in the lipidome of HDL subpopulations in FAID in relationship to antiatherogenic activities. METHODS: Five HDL subfractions were isolated by ultracentrifugation from plasma of FAID Caucasian patients (n = 5) and age-matched healthy normolipidemic Caucasian controls (n = 8), and the HDL lipidome (160 molecular species of 9 classes of phospholipids and sphingolipids) was quantitatively evaluated. RESULTS: Increased concentrations of numerous molecular species of lysophosphatidylcholine (up to 12-fold), ceramides (up to 3-fold), phosphatidylserine (up to 34-fold), phosphatidic acid (up to 71-fold), and phosphatidylglycerol (up to 20-fold) were detected throughout all five HDL subpopulations as compared with their counterparts from controls, whereas concentrations of phosphatidylethanolamine species were decreased (up to 5-fold). Moderately to highly abundant, within their lipid class, species of phosphatidylcholine, sphingomyelin, phosphatidylinositol, phosphatidylethanolamine, phosphatidylserine, and ceramide featuring multiple unsaturations were primarily affected by apoA-I deficiency; their HDL content, particularly that of phosphatidylcholine (34:2), was strongly correlated with HDL function, impaired in FAID. Metabolic pathway analysis revealed that sphingolipid, glycerophospholipid, and linoleic acid metabolism was significantly affected by FAID. CONCLUSION: These data reveal that altered content of specific phospholipid and sphingolipid species is linked to deficient antiatherogenic properties of HDL in FAID.

7.
Mycoses ; 62(6): 542-550, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30887582

RESUMO

BACKGROUND: Reports on the consumption of systemic antifungal drugs on a national level are scarce although of high interest to compare trends and the associated epidemiology in other countries and to assess the need for antifungal stewardship programmes. OBJECTIVES: To estimate patterns of Belgian inpatient and outpatient antifungal use and provide reference data for other countries. METHODS: Consumption records of antifungals were collected in Belgian hospitals between 2003 and 2016. Primary healthcare data were available for the azoles for the period 2010-2016. RESULTS: The majority of the antifungal consumption resulted from prescriptions of fluconazole and itraconazole in the ambulatory care while hospitals were responsible for only 6.4% of the total national consumption and echinocandin use was limited. The annual average antifungal consumption in hospitals decreased significantly by nearly 25% between 2003 and 2016, due to a decrease solely in non-university hospitals. With the exception of specialised burn centres, antifungals are mostly consumed at ICUs and internal medicine wards. A significant decline was also observed in the consumption of azoles in primary health care, attributed to itraconazole. The major part of azoles was prescribed by generalists followed by dermatologists. CONCLUSIONS: In spite of the downward trend in annual use of systemic antifungal drugs, Belgium remains one of the biggest consumers in Europe.


Assuntos
Antifúngicos/uso terapêutico , Uso de Medicamentos/estatística & dados numéricos , Micoses/tratamento farmacológico , Bélgica , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino
8.
Med Mycol ; 57(6): 773-780, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30535052

RESUMO

Aspergillus section Nigri is a taxonomically difficult but medically and economically important group. In this study, an update of the taxonomy of A. section Nigri strains within the BCCM/IHEM collection has been conducted. The identification accuracy of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was tested and the antifungal susceptibilities of clinical isolates were evaluated. A total of 175 strains were molecularly analyzed. Three regions were amplified (ITS, benA, and caM) and a multi-locus phylogeny of the combined loci was created by using maximum likelihood analysis. The in-house MALDI-TOF MS reference database was extended and an identification data set of 135 strains was run against a reference data set. Antifungal susceptibility was tested for voriconazole, itraconazole, and amphotericin B, using the EUCAST method. Phylogenetic analysis revealed 18 species in our data set. MALDI-TOF MS was able to distinguish between A. brasiliensis, A. brunneoviolaceus, A. neoniger, A. niger, A. tubingensis, and A. welwitschiae of A. sect. Nigri. In the routine clinical lab, isolates of A. sect. Nigri are often identified as A. niger. However, in the clinical isolates of our data set, A. tubingensis (n = 35) and A. welwitschiae (n = 34) are more common than A. niger (n = 9). Decreased antifungal susceptibility to azoles was observed in clinical isolates of the /tubingensis clade. This emphasizes the importance of identification up to species level or at least up to clade level in the clinical lab. Our results indicate that MALDI-TOF MS can be a powerful tool to replace classical morphology.

9.
Phys Rev Lett ; 121(23): 232501, 2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30576180

RESUMO

We show that the measured intrinsic octupole moments of ^{220}Rn, ^{224}Ra, and ^{226}Ra constrain the intrinsic Schiff moments of ^{225}Ra, ^{221}Rn, ^{223}Rn, ^{223}Fr, ^{225}Ra, and ^{229}Pa. The result is a dramatically reduced uncertainty in intrinsic Schiff moments. Direct measurements of octupole moments in odd nuclei will reduce the uncertainty even more. The only significant source of nuclear-physics error in the laboratory Schiff moments will then be the intrinsic matrix elements of the time-reversal noninvariant interaction produced by CP-violating fundamental physics. Those matrix elements are also correlated with octupole moments, but with a larger systematic uncertainty.

10.
Artigo em Inglês | MEDLINE | ID: mdl-29784839

RESUMO

Candida glabrata is a major cause of candidemia in immunocompromised patients and is characterized by a high-level of fluconazole resistance. In the present study, the acquisition of antifungal resistance and potential clonal spread of C. glabrata were explored at a single center over a 12-year period by analyzing 187 independent clinical C. glabrata bloodstream isolates. One strain was found to be micafungin resistant due to a mutation in the FKS2 gene. Fluconazole resistance remained stable throughout the period and was observed in 20 (10.7%) of the isolates. An analysis of the antifungal consumption data revealed that recent prior exposure to fluconazole increased the risk to be infected by a resistant strain. In particular, the duration of the treatment was significantly longer for patients infected by a resistant isolate, while the total and mean daily doses received did not impact the acquisition of resistance in C. glabrata No link between genotype and resistance was found. However, multilocus variable-number tandem-repeat analyses indicated a potential intrahospital spread of some isolates between patients. These isolates shared the same genetic profiles, and infected patients were hospitalized in the same unit during an overlapping period. Finally, quantitative real-time PCR analyses showed that, unlike that for other ABC efflux pumps, the expression of CgCDR1 was significantly greater in resistant strains, suggesting that it would be more involved in fluconazole (FLC) resistance. Our study provides additional evidence that the proper administration of fluconazole is required to limit resistance and that strict hand hygiene is necessary to avoid the possible spreading of C. glabrata isolates between patients.


Assuntos
Antifúngicos/farmacologia , Candida glabrata/efeitos dos fármacos , Fluconazol/farmacologia , Bélgica , Candida glabrata/genética , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Testes de Sensibilidade Microbiana
12.
Mycoses ; 61(2): 127-133, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29024057

RESUMO

Candidaemia is an important health problem in immunocompromised patients with an epidemiology varying with region, period and patient population involved. The occurrence of candidaemia and the associated species distribution over a 12-year period at a large tertiary care centre in Belgium were analysed. The trend in incidence in the intensive care units (ICUs) and non-ICUs was investigated as well as the influence of antifungal exposure on the species distribution. From 2004 until 2015, 865 candidaemia episodes occurred in 826 patients at the University Hospitals Leuven. Candida albicans (59%) remained the most important cause of candidaemia, followed by C. glabrata (22.4%) and C. parapsilosis (8%). The mean incidence in the whole hospital was 1.48 per 10 000 patient days (PD). The incidence in ICUs increased reaching up to 10.7 per 10 000 PD whereas in the non-ICUs, the incidence decreased. Prior exposure to fluconazole and echinocandins was associated with candidaemia caused by less susceptible species. Candidaemia incidence increased in the whole hospital, driven by ICUs. Surveillance of candidaemia epidemiology on a local scale is of high value to guide empirical treatment strategies.


Assuntos
Antifúngicos/uso terapêutico , Candida/classificação , Candida/isolamento & purificação , Candidemia/epidemiologia , Candidemia/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bélgica/epidemiologia , Criança , Pré-Escolar , Equinocandinas/uso terapêutico , Feminino , Fluconazol/uso terapêutico , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Centros de Atenção Terciária , Adulto Jovem
13.
Acta Crystallogr A Found Adv ; 73(Pt 5): 373-374, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28862162
14.
BMC Microbiol ; 17(1): 25, 2017 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-28143403

RESUMO

BACKGROUND: Several Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry protocols, which differ in identification criteria, have been developed for mold and dermatophyte identification. Currently, the most widely used approach is Bruker technology, although no consensus concerning the log(score) threshold has been established. Furthermore, it remains unknown how far increasing the number of spots to compare results might improve identification performance. In this study, we used in-house and Bruker reference databases as well as a panel of 422 isolates belonging to 126 species to test various thresholds. Ten distinct identification algorithms requiring one to four spots were tested. RESULTS: Our findings indicate that optimal results were obtained by applying a decisional algorithm in which only the highest score of four spots was taken into account with a 1.7 log(score) threshold. Testing the entire panel enabled identification of 87.41% (in-house database) and 35.15% (Bruker database) of isolates, with a positive predictive value (PPV) of 1 at the genus level for both databases as well as 0.89 PPV (in-house database) and 0.72 PPV (Bruker database) at the species level. Applying the same rules to the isolates for which the species were represented by at least three strains in the database enabled identification of 92.1% (in-house database) and 46.6% (Bruker database) of isolates, with 1 PPV at the genus level for both databases as well as 0.95 PPV (in-house database) and 0.93 PPV (Bruker database) at the species level. CONCLUSIONS: Depositing four spots per extract and lowering the threshold to 1.7, a threshold which is notably lower than that recommended for bacterial identification, decreased the number of unidentified specimens without altering the reliability of the accepted results. Nevertheless, regardless of the criteria used for mold and dermatophyte identification, commercial databases require optimization.


Assuntos
Bases de Dados Factuais , Fungos/isolamento & purificação , Técnicas de Tipagem Micológica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Algoritmos , Sequência de Bases , DNA Fúngico , Fungos/classificação , Genes Fúngicos , Reprodutibilidade dos Testes
15.
Prenat Diagn ; 36(5): 397-406, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26850935

RESUMO

BACKGROUND: Achondroplasia is generally detected by abnormal prenatal ultrasound findings in the third trimester of pregnancy and then confirmed by molecular genetic testing of fetal genomic DNA obtained by aspiration of amniotic fluid. This invasive procedure presents a small but significant risk for both the fetus and mother. Therefore, non-invasive procedures using cell-free fetal DNA in maternal plasma have been developed for the detection of the fetal achondroplasia mutations. METHODS: To determine whether the fetus carries the de novo mis-sense genetic mutation at nucleotide 1138 in FGFR3 gene involved in >99% of achondroplasia cases, we developed two independent methods: digital-droplet PCR combined with minisequencing, which are very sensitive methods allowing detection of rare alleles. RESULTS: We collected 26 plasmatic samples from women carrying fetus at risk of achondroplasia and diagnosed to date a total of five affected fetuses in maternal blood. The sensitivity and specificity of our test are respectively 100% [95% confidence interval, 56.6-100%] and 100% [95% confidence interval, 84.5-100%]. CONCLUSIONS: This novel, original strategy for non-invasive prenatal diagnosis of achondroplasia is suitable for implementation in routine clinical testing and allows considering extending the applications of these technologies in non-invasive prenatal diagnosis of many other monogenic diseases. © 2016 John Wiley & Sons, Ltd.


Assuntos
Acondroplasia/diagnóstico , DNA/sangue , Testes para Triagem do Soro Materno , Acondroplasia/sangue , Acondroplasia/genética , Algoritmos , Estudos de Casos e Controles , DNA/genética , Feminino , Humanos , Mutação de Sentido Incorreto , Reação em Cadeia da Polimerase , Gravidez , Diagnóstico Pré-Natal , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Sensibilidade e Especificidade , Análise de Sequência de DNA
16.
Med Mycol ; 52(8): 826-34, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25349253

RESUMO

The identification of filamentous fungi by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) relies mainly on a robust and extensive database of reference spectra. To this end, a large in-house library containing 760 strains and representing 472 species was built and evaluated on 390 clinical isolates by comparing MALDI-TOF MS with the classical identification method based on morphological observations. The use of MALDI-TOF MS resulted in the correct identification of 95.4% of the isolates at species level, without considering LogScore values. Taking into account the Brukers' cutoff value for reliability (LogScore >1.70), 85.6% of the isolates were correctly identified. For a number of isolates, microscopic identification was limited to the genus, resulting in only 61.5% of the isolates correctly identified at species level while the correctness reached 94.6% at genus level. Using this extended in-house database, MALDI-TOF MS thus appears superior to morphology in order to obtain a robust and accurate identification of filamentous fungi. A continuous extension of the library is however necessary to further improve its reliability. Indeed, 15 isolates were still not represented while an additional three isolates were not recognized, probably because of a lack of intraspecific variability of the corresponding species in the database.


Assuntos
Bases de Dados Factuais , Fungos/isolamento & purificação , Técnicas de Tipagem Micológica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Fungos/química , Humanos , Micoses/diagnóstico , Micoses/microbiologia , Reprodutibilidade dos Testes
17.
Biol Bull ; 223(2): 217-25, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23111133

RESUMO

The shelter of the tube-dwelling polychaete Sabellaria alveolata is composed of mineral particles assembled with spots of a proteinaceous cement. The adhesive proteins constituting the cement were identified on the basis of their sequence similarity with proteins of a phylogenetically related species, Phragmatopoma californica. Two positively charged proteins, Sa-1 and Sa-2, share common features: they both have a mass of 22 kDa; are rich in glycine, tyrosine and basic residues; and show repeated peptide motifs. The consensus repeat of Sa-1 is KGAYGAKGLGYGNKAGYGAYG (occurring 6-8 times), while Sa-2 displays the consensus heptapeptide VHKAAWG (5 times) and undecapeptide VHKAAGYGGYG (8 times). Two variants of a serine-rich protein, Sa-3A (22 kDa) and Sa-3B (21 kDa), were also identified. Their serine residues account for 75 mol% and are probably phosphorylated, meaning that Sa-3 is very acidic and negatively charged. Moreover, tyrosine residues of all adhesive proteins are presumably modified into DOPA. Although protein sequences are not well-conserved between S. alveolata and P. californica, their main characteristics (including amino acid composition, post-translational modifications, repeated patterns, isoelectric point, and mass) are shared by both species. This suggests that these features are more important for their function than the primary structure of the proteins. The mRNA abundance for each protein was estimated by quantitative real-time PCR, revealing relative expression levels of about 5, 11, 1.5, and 1 for Sa-1, -2, -3A, and -3B, respectively. These levels could be indicative of charge neutralization phenomena or could reflect their function (interface vs. bulk) in the cement.


Assuntos
Poliquetos/genética , Poliquetos/metabolismo , Proteínas/genética , Proteínas/metabolismo , Adesivos Teciduais/metabolismo , Aminoácidos/análise , Animais , Perfilação da Expressão Gênica , Dados de Sequência Molecular , Peso Molecular , Proteínas/química , Reação em Cadeia da Polimerase em Tempo Real , Sequências Repetitivas de Aminoácidos , Análise de Sequência de DNA , Adesivos Teciduais/química
18.
Acta Crystallogr A ; 68(Pt 6): 675-86, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23075610

RESUMO

New crystallographic tools were developed to access a more precise description of the spin-dependent electron density of magnetic crystals. The method combines experimental information coming from high-resolution X-ray diffraction (XRD) and polarized neutron diffraction (PND) in a unified model. A new algorithm that allows for a simultaneous refinement of the charge- and spin-density parameters against XRD and PND data is described. The resulting software MOLLYNX is based on the well known Hansen-Coppens multipolar model, and makes it possible to differentiate the electron spins. This algorithm is validated and demonstrated with a molecular crystal formed by a bimetallic chain, MnCu(pba)(H(2)O)(3)·2H(2)O, for which XRD and PND data are available. The joint refinement provides a more detailed description of the spin density than the refinement from PND data alone.

19.
J Invertebr Pathol ; 100(2): 127-30, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19041326

RESUMO

The bacterial community associated with skin lesions of the sea urchin Tripneustes gratilla was investigated using 16S ribosomal RNA gene cloning and fluorescent in situ hybridization (FISH). All clones were classified in the Alphaproteobacteria, Gammaproteobacteria and Cytophaga-Flexibacter-Bacteroides (CFB) bacteria. Most of the Alphaproteobacteria were related to the Roseobacter lineage and to bacteria implicated in marine diseases. The majority of the Gammaproteobacteria were identified as Vibrio while CFB represented only 9% of the total clones. FISH analyses showed that Alphaproteobacteria, CFB bacteria and Gammaproteobacteria accounted respectively for 43%, 38% and 19% of the DAPI counts. The importance of the methods used is emphasized.


Assuntos
Alphaproteobacteria/isolamento & purificação , Cytophaga/isolamento & purificação , Gammaproteobacteria/isolamento & purificação , Ouriços-do-Mar/microbiologia , Alphaproteobacteria/classificação , Alphaproteobacteria/fisiologia , Animais , Clonagem Molecular , Cytophaga/classificação , Cytophaga/fisiologia , DNA Bacteriano/química , Gammaproteobacteria/classificação , Gammaproteobacteria/fisiologia , Hibridização in Situ Fluorescente , RNA Ribossômico 16S/química
20.
J Invertebr Pathol ; 98(2): 136-47, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18191940

RESUMO

The microbial communities involved in the bald sea urchin disease of the echinoid Paracentrotus lividus are investigated using culture-independent techniques. Lesions of diseased specimens from two locations in France, La Ciotat (Mediterranean Sea) and Morgat (Atlantic Ocean), are examined by Scanning Electron Microscopy (SEM) and the diversity of their microbiota is analysed by Denaturing Gradient Gel Electrophoresis (DGGE) and 16S rRNA gene clones libraries construction. Microscopic observations demonstrated that only the central area of the lesions is invaded by bacteria but not the peripheral zone and the surrounding healthy tissues. Molecular analysis identified at least 24 bacterial genomospecies in bald sea urchin lesions: 5 are Alphaproteobacteria, 10 are Gammaproteobacteria, 8 are CFB bacteria and 1 is a Fusobacteria. Out of them, 4 are observed in both locations while 10 occur only in the Atlantic Ocean and 10 only in the Mediterranean Sea. Gammaproteobacteria are the most represented in clones libraries from both locations, with respectively 65% and 43% of the total clones. CFB and Alphaproteobacteria accounted for the majority of the remaining clones and were detected by DGGE in virtually all samples from both stations. Our results demonstrate that bacterial communities observed on diseased individuals of the same echinoid species but originating from distinct locations are not similar and thus support the hypothesis that bacteria involved in the worldwide echinoid disease commonly called the bald sea urchin disease are opportunistic and not specific.


Assuntos
Bactérias/classificação , Infecções Bacterianas/patologia , Infecções Bacterianas/veterinária , Paracentrotus/microbiologia , Animais , Oceano Atlântico , Bactérias/genética , Bactérias/isolamento & purificação , Infecções Bacterianas/epidemiologia , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Mar Mediterrâneo , Microscopia Eletrônica de Varredura , Reação em Cadeia da Polimerase , RNA Bacteriano/análise , RNA Ribossômico 16S/análise
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